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Semiconductor lab

Semiconductor Processing Lab Dedicated

ECE opened its new Micron Technology Semiconductor Processing Laboratory this fall. The Class 1,000/10,000 clean-room laboratory is the latest of the new facilities operated by Virginia Tech’s multidisciplinary Microelectronics, Optoelectronics and Nanotechnology (MicrON) Group.

The research and teaching laboratory is named for Micron Technology, in recognition of the firm’s $750,000 gift that provided the final funds that allowed the laboratory’s completion. The cleanroom joins several other of Tech’s MicrON Group facilities: a metal-organic chemical vapor depositions (MOCVD) laboratory, an electronic/optoelectronic materials laboratory, and a device characterization laboratory. An electronic packaging laboratory is also available.

A “black box” system of modeling

Researchers in the Center for Power Electronics (CPES) have developed a “black-box” modeling approach for designing new power electronics-based electric energy distribution systems. The new method diverges from the conventional “white-box” approach, which requires detailed knowledge of the converter structure and parameters. However, the growing use of power electronics in distribution systems has made design more complicated: the size and complexity of future systems alone make white-box modeling difficult. Another complication is that converters are commercially available from numerous different vendors, who provide little or no information about the internal structure of their products.

The CPES approach is based entirely on the terminal characteristics of power converters, using a simple set of small-signal measurements to construct the low-frequency model without requiring any knowledge of the converter structure or any of its internal parameters. Called the black-box modular-terminal-behavioral modeling methodology, the model captures the information without neglecting parasitics or simplifying the converter internal operation, as is common with conventional reduced-order models. The CPES approach is modular, enabling computationally efficient analysis of all electrical phenomena in the system.

High-speed analog-to-digital converters

Bradley Fellow Mark Lehne is investigating new analog-to-digital conversion-circuit architectures that improve a broadband wireless transceiver’s ability to efficiently detect information in the presence of strong interfer­ence. The goal is better overall performance while allowing for higher data rates and more intelligent transceivers. In order to coexist with legacy narrow-band transceivers, high-speed analog-to-digital converters must allow the receiver to operate with sufficient fidelity to detect target signals while identifying and rejecting narrow-band interference.

Power System

Testbed developed for self-sustained, zero-emissions power system

To facilitate communications in remote locations, CPES researchers have developed a self-contained, 3 kW, autonomous hybrid power system for data communications in remote locations. The testbed system serves as a demonstration of an electric power system for future self-sustained, zero-emission applications. The scaled-down generic electronic power distribution system is representative of systems that could be used for future homes, data centers, hybrid electric cars, aircraft, and ships.

The testbed incorporates representative renewable sources, power converter-based loads, and a grid-interfaced controllable distribution network, in order to evaluate system-level impacts of CPES technologies.

As implemented in the CPES laboratory, the testbed includes a solar photovoltaic source simulator and AC grid connection as energy sources, lead-acid batteries, a battery charger, an AC transfer switch, and DC-AC inverter, and mixed AC-DC power distribution with computer-controlled measurement and supervision as the energy management system.

The system is designed to provide uninterrupted energy supply to the data servers and air-conditioning electrical loads.

Power System

Mapping power electronics development

Power electronics researchers from around the world are collaborating on how to focus efforts to ensure that power electronics helps industries and countries globally to reduce energy consumption and environmental impact.

Power electronics has emerged as an enabling technology in this global effort.

As one of the largest power electronics research groups in the world, CPES has taken the lead on gathering academic and industrial researchers to develop a roadmap for development. CPES has organized two annual roadmap workshops, the most recent during October 2006. The roadmap effort is funded by an NSF supplemental grant.